Well, this won't fit in the bag, but I really like to bring the Boppy. I use it not just for nursing but holding the baby in the bed. I am always so worried I will fall asleep and the baby will fall onto the floor, so this is just a little way to keep her safer. A pouch is good, too.
I also finally figured out that I need to bring really comfortable clothes to wear (old ones, preferably black since you'll be messy/bleeding) instead of the hospital gown. When I started doing that, I felt like a new person, or rather, myself, in the hospital. MUCH more relaxing to walk around, nurse, etc. It is so nice to talk to your ped and MW feeling normal. Believe it or not, makeup is helpful to bring, too!
Also nice to bring would be DVDs and a laptop/portable DVD player unless your hospital has a good one. Hospital TV is so boring. Books and magazines, plus some snacks, are handy. The last time I finished a book was when I was in the hospital.